Introduce new WebApp header style for hosted apps and fizzy apps on ash.

chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.h

Index: chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.h
diff --git a/chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.h b/chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.h
index 70c984d21a2db1552df8d059266de2e430358343..660c58c3104d9241b9983a82da55fca116eca9c7 100644
--- a/chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.h
+++ b/chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.h
@@ -8,13 +8,16 @@
 #include "ash/shell_observer.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
+#include "chrome/browser/command_observer.h"
 #include "chrome/browser/ui/views/frame/browser_non_client_frame_view.h"
 #include "chrome/browser/ui/views/tab_icon_view_model.h"
+#include "ui/views/controls/button/button.h"
 
 class TabIconView;
 
 namespace ash {
 class FrameBorderHitTestController;
+class FrameCaptionButton;
 class FrameCaptionButtonContainerView;
 class HeaderPainter;
 }
@@ -23,10 +26,11 @@ class ImageButton;
 class ToggleImageButton;
 }
 
-class BrowserNonClientFrameViewAsh
-    : public BrowserNonClientFrameView,
-      public ash::ShellObserver,
-      public chrome::TabIconViewModel {
+class BrowserNonClientFrameViewAsh : public BrowserNonClientFrameView,
+                                     public ash::ShellObserver,
+                                     public chrome::TabIconViewModel,
+                                     public CommandObserver,
+                                     public views::ButtonListener {
  public:
   static const char kViewClassName[];
 
@@ -68,6 +72,13 @@ class BrowserNonClientFrameViewAsh
   virtual bool ShouldTabIconViewAnimate() const OVERRIDE;
   virtual gfx::ImageSkia GetFaviconForTabIconView() OVERRIDE;
 
+  // CommandObserver:
+  virtual void EnabledStateChangedForCommand(int id, bool enabled) OVERRIDE;
+
+  // views::ButtonListener:
+  virtual void ButtonPressed(views::Button* sender,
+                             const ui::Event& event) OVERRIDE;
+
  private:
   FRIEND_TEST_ALL_PREFIXES(BrowserNonClientFrameViewAshTest, WindowHeader);
   FRIEND_TEST_ALL_PREFIXES(BrowserNonClientFrameViewAshTest,
@@ -98,6 +109,11 @@ class BrowserNonClientFrameViewAsh
   // scheme than browser windows.
   bool UsePackagedAppHeaderStyle() const;
 
+  // Returns true if the header should be painted with a WebApp header style.
+  // The WebApp header style has a back button and title along with the usual
+  // accoutrements.
+  bool UseWebAppHeaderStyle() const;
+
   // Layout the incognito icon.
   void LayoutAvatar();
 
@@ -115,9 +131,15 @@ class BrowserNonClientFrameViewAsh
   // the packaged app header style.
   void PaintContentEdge(gfx::Canvas* canvas);
 
+  // Update the state of the back button.
+  void UpdateBackButtonState(bool enabled);
+
   // View which contains the window controls.
   ash::FrameCaptionButtonContainerView* caption_button_container_;
 
+  // The back button for web app style header.
+  ash::FrameCaptionButton* web_app_back_button_;
+
   // For popups, the window icon.
   TabIconView* window_icon_;